Jack2 on DROPS/L4 (Diploma thesis) | towards a truly real-time capable FOSS audio distribution - Linux-audio-announce

16 Apr 2009

Dear Linux Audio Developers,

as indicated by Stéphane in his presentation [1] he gave at LAC2009 today, I 
finally handed in my diploma thesis, which I announced here [2]. You can 
download the full text of the thesis here:

	<http://www1.inf.tu-dresden.de/~s3418892/diplom.pdf> [3].

If you want to take a glimpse at the code, you can get a (still very dirty) 
snapshot of the code here [4]. 

The abstract of the thesis:

...
  Several available free software audio solutions were
analyzed, and
 Jackdmp—a C++ reimplementation of the renowned JACK Audio Connection
 Kit—was selected as the most appropriate solution for a real-time audio
 architecture on DROPS. The JACK sound architecture provides the lowest
 processing latency possible on a desktop computer for a given set of sound
 card parameters. It reduces the latency jitter caused by software to zero
 and synchronizes streams at sample accuracy. 
...
      A real-time admission scheme for JACK clients is
proposed.
 The execution time of different typical JACK clients was analyzed with
 measurements to validate the assumptions the proposal is based on,
 but also to gain further knowledge about their timing behavior. 
 The measurements showed that the condition set by Paul Davis—the 
 time to process a client must be a linear function of the buffer size—holds
 for all tested clients. 
...
     Jackdmp was ported to DROPS. The developed design
of the port and its
 implementation is documented here. Measurements showed that—although
 the real-time performance of the Linux kernel is continously being improved
 in the mainline and on special external branches—DROPS can provide a
 signaling latency that is two times lower on average than the values that
 can be achieved on the same machine running with a low latency patched
 Linux kernel. Thus, it can be stated that DROPS is well-suited for
 real-time audio processing and that the pursued path to use it as the
 foundation of a truly real-time capable audio workstation should be
 followed. 
As of the project's future: I will try to get the ALSA driver and the 
connection with L4Linux working until the presentation of the project (no 
date set so far, but probably in 2--4 weeks or so). If all works well, we 
will consider releasing a demo disc and / or a Youtube demonstration for 
interested developers and power users of the system then. And then we'll 
see :).

Kind regards --- and those of you who are in Parma: Have an interesting 
conference and a great time in Italy! ---,

micu
===============================================================
[1]<http://linuxaudio.de/lac2009/JACK2_LAC_2009_slides.pdf>
[2]<http://lists.linuxaudio.org/pipermail/linux-audio-dev/2008-July/02138…
[3]<http://www1.inf.tu-dresden.de/~s3418892/diplom.pdf>
   // This is only a temporal location, I will inform you about the final 
      location here as soon as the document is published there.
[4]<http://www1.inf.tu-dresden.de/~s3418892/code_snapshot_(still%20dirty).tar.gz>
-- 
GnuPG:		https://www1.inf.tu-dresden.de/~s3418892/micuintus.asc
Fingerprint:	1A15 A480 1F8B 07F6 9D12 3426 CEFE 7455 E4CB 4E80

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